Quoting johnps11@bigpond.com:
Hi Stan!
Have you tried using the -mmap option when starting Squeak? I notice that according to the squeakvm man page:
squeak uses a dynamic heap by default with the maximum size set to 75% of the available virtual memory or 1 gigabyte, whichever is smaller.
Perhaps Windows doesn't have this limit. Is one instance of Object bigger than 200 bytes? If so you'd expect it to oom.
Assuming you have 2 gig of virtual memory, try starting the VM with
-mmap 1500m
as an option and see if it goes further.
Note you can temporarily increase your virtual memory by running (as root):
dd if=/dev/zero of=/tmp/swapfile bs=1024 count=1M mkswap /tmp/swapfile swapon /tmp/swapfile
This will increase your VM by 1 Gigabyte - note that on an intel machine your VM is usually restricted to a max of about 2gig (unless you start the kernel with the right options, and you have a large memory machine, and you have a kernel built to support over 4gig of memory). I'm also assuming you have a spare gig of space in /tmp . This lasts till you reboot or until you run
swapoff /tmp/swapfileas root.
You'll also want to rm that file when you've finished!
I guess that the *nix ports have this restriction for the squeak VM because of the assumption that apps should play nice and not suck the system into oblivion!
It might also be instructive to run
vmstat 10 20in another terminal while you allocate your insanely large array. You'll be able to see if the "freeze" is simply massive disk usage as linux goes crazy seeking inside the swapfile - you are allocating 100 million references before you even start to allocate Objects! Read the man page on vmstat on how to interpret it if you don't know the command.
I hope this helps, and doesn't just confuse...
John
http://lists.squeakfoundation.org/mailman/listinfo/beginners
Hi John, not confusing- an excellent response, thanks.
With the memory option it also cruises on under Linux, until it freezes at 70 million objects.
While it's still loading vmstat shows:
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 2 0 32528 38552 22792 758560 0 0 183 520 295 2399 66 9 17 7 3 0 32528 38420 22800 758568 0 0 0 3 254 1779 92 8 0 0 4 0 32528 38420 22804 758568 0 0 0 6 234 2100 93 7 0 0 4 0 32528 38420 22804 758568 0 0 0 0 239 2125 93 7 0 0 2 0 32528 38420 22808 758568 0 0 0 0 233 1379 95 5 0 0 2 0 32528 38420 22816 758568 0 0 0 1 251 2255 92 8 0 0 2 0 32528 38296 22824 758568 0 0 0 3 244 1963 94 6 0 0 4 0 32528 38296 22824 758568 0 0 0 0 230 1863 93 7 0 0 5 0 32528 38296 22832 758568 0 0 0 4 234 2108 91 9 0 0 2 0 32528 38296 22840 758568 0 0 0 12 228 1616 94 6 0 0 4 0 32528 38296 22840 758568 0 0 0 0 234 2142 93 7 0 0 2 0 32528 36608 22680 751824 0 0 0 1 228 1639 94 6 0 0 1 0 32528 36608 22680 751824 0 0 0 7 234 2128 92 8 0 0 3 0 32528 36484 22680 751824 0 0 0 3 248 2170 92 9 0 0 2 0 32528 39080 22560 749472 0 0 2 4 231 1610 93 7 0 0 4 0 32528 35104 22560 749584 0 0 0 0 239 2137 89 11 0 0 3 0 32528 34636 22560 749584 0 0 0 0 236 2084 92 8 0 0 3 0 32528 34960 22568 749584 0 0 0 4 233 1898 93 7 0 0 4 0 32528 38956 22568 749584 0 0 0 1 238 2277 90 10 0 0 2 0 32528 36724 22568 749584 0 0 0 0 227 1719 94 6 0 0
Without the -mmap option, once the image has frozen, vmstat shows:
r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 32528 41884 23220 703504 0 0 130 370 272 2402 74 9 12 5 1 0 32528 41624 23228 703512 0 0 0 4 215 1094 97 3 0 0 1 0 32528 41628 23228 703512 0 0 0 0 186 703 98 2 0 0 1 0 32528 41628 23228 703512 0 0 0 0 179 667 97 3 0 0 1 0 32528 41628 23236 703512 0 0 0 6 180 668 97 3 0 0 1 0 32528 41628 23244 703512 0 0 0 4 180 667 97 3 0 0 1 0 32528 41628 23244 703512 0 0 0 0 179 667 98 2 0 0 1 0 32528 41628 23244 703512 0 0 0 0 204 765 96 4 0 0 1 0 32528 41628 23244 703512 0 0 0 2 205 1019 97 3 0 0 1 0 32528 41628 23260 703516 0 0 0 6 180 665 97 3 0 0 1 0 32528 41628 23268 703516 0 0 0 1 179 658 98 2 0 0 1 0 32528 41628 23276 703520 0 0 0 6 180 657 97 3 0 0 1 0 32528 41628 23276 703520 0 0 0 3 180 655 97 3 0 0 1 0 32528 41628 23276 703520 0 0 0 0 180 654 97 3 0 0 1 0 32528 41628 23280 703520 0 0 0 0 179 656 97 3 0 0 1 0 32528 41628 23280 703520 0 0 0 0 179 659 98 3 0 0 1 0 32528 41628 23288 703520 0 0 0 1 179 653 97 3 0 0 1 0 32528 41628 23288 703520 0 0 0 0 179 654 98 2 0 0 1 0 32528 41628 23288 703520 0 0 0 0 179 654 98 2 0 0 1 0 32528 41628 23296 703520 0 0 0 3 180 658 98 2 0 0.
Nothing obviously different to me.
At least I can work around this as long as I keep sizes moderate.
Thanks again, Stan